I had that problem in the past so I tracked sets an weights for a good... idk, 6-8 months. After Christmas break I stopped writing it down as I was doing it and just made a mental note, then created a FB note later that day for my own record keeping. After 3-4 weeks I stopped doing that too, I felt it was tying me down. Since I've just been trying to remember and keep it mixed up. It's going ok but it's forced me to focus on the abstract goal of burn out rather than specific numbers on some workouts I don't do as frequently and therefore can't exactly remember my maxes on. I guess in some ways it has LIMITED the diversity of my workout rather than assisted it. I might cycle back to recording it more diligently this summer if I feel like it's holding me back, but so far my maxes are still gaining... which, of course isn't the end-all/be-all of fitness, but it's as decent a benchmark as anything I suppose.